1. Field of the Invention
The present invention relates to engine traction control for preventing the wheels of a vehicle from slipping during acceleration.
2. Description of the Related Art
When slip prevention on a slippery road surface or upon acceleration (e.g., start) of a vehicle mounting a high-output engine is performed by controlling an engine output, the following methods are known. In one method, an engine output is largely decreased in order to immediately stop a slip upon detection of the slip. When a slip amount of a differential value of a driving wheel velocity is decreased below a predetermined value, the engine output is restored (method A). In another method, in order to achieve smooth control, the engine output is restored slowly (method B). In still another method, a slip of a vehicle is slowly suppressed (method C: Japanese Patent Disclosure (Kokai) No. 61-115729).
However, in method A, since the engine output is restored immediately after the slip is stopped, a slip occurs again. In method B, it takes too much time to restore a decreased engine output to an optimal value, resulting in an acceleration loss. In method C, a slip time is long, resulting in poor operability.